Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 233F7C678D5 for ; Wed, 8 Mar 2023 07:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229819AbjCHHc2 (ORCPT ); Wed, 8 Mar 2023 02:32:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229579AbjCHHcT (ORCPT ); Wed, 8 Mar 2023 02:32:19 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7DF2A336C for ; Tue, 7 Mar 2023 23:32:14 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id d185-20020a25e6c2000000b008fa1d22bd55so17083990ybh.21 for ; Tue, 07 Mar 2023 23:32:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1678260734; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=1HJMLloX8l3VEo0+22HUaFfPeUdekf+/4qykWWC+d8Q=; b=sV1RKOnV7SF9Z0hXW96OjKAFskv9QxYAq2DIgZs6X3jgNThSZn8PERZBPg+ExcAz8q L+yd8AyQO80kF1xo0A5IYqIKP+g037KRTtaDB0s0ruMuH8v/qos7aw9bx8KvIhxL+QdZ nbI3yF7wgTcPM6xv17msJrDyGBFNO/0cm5d3tj0H7gH+XqK/a/fLx4qnF3NtThvqlevo vF84/hm97EKEGvrDziTCNG5cNrIm0gZHhMjxUyXWZuVHZO2MZ8V9XVcbWhj9kj78mjJl qTLc8o1g+gKHaL5FlMjaaGPY8tqvJmhKhA0uYKy5ylyGYJZBd0LqA4JdzqXDGC/TunWj 7uyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678260734; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1HJMLloX8l3VEo0+22HUaFfPeUdekf+/4qykWWC+d8Q=; b=nqw5L0UnT+QQDxEErPU8piGziO0+YvlpBKyw6oT5NGWfnvQ+Bji2PdQN//w6iZqGl9 1STFli6une0VU+//6LqBj54QYEUiWvCAlbwJT3iTBzyKNfh53PWJ7+pg1ddLN54SCvNx vrZWuiN6pu8bjba4LQl3+UbEbTR00uwv+mcVnLGeE3gTRKW7gH/PGlKvqApVFOP2i6OD eMIABJLpQRc1imuYzUsMitWpqbQx5QWrtBOePsUNGT8FunbROTeTBaBkiTnJEnfGngoE COvYFYQPzRBQgl/9EjdtRcf2mTpla8oMQWvtb5LUWMPWF5aSfOu8Xjdy6b/n9IHbzl95 eewg== X-Gm-Message-State: AO0yUKW9qbsQn/6DZXPa48OpBFzMxEkfRhiE5RCYqf2dPhZkrBinNA5n 8Kf1dNS5iYdXE+qGidoeVRSZLsnFC4g= X-Google-Smtp-Source: AK7set9ioPK6MoaQWwmMvAEI8zCmlOuHUBwUXXK8WXboKLBqaMGLdSnUaq9+l4rgvMN20bhtpnMM0D5mYlQ= X-Received: from avagin.kir.corp.google.com ([2620:0:1008:11:b53:99a6:b4fe:b30b]) (user=avagin job=sendgmr) by 2002:a05:6902:151:b0:afa:d8b5:8e82 with SMTP id p17-20020a056902015100b00afad8b58e82mr8271697ybh.6.1678260734085; Tue, 07 Mar 2023 23:32:14 -0800 (PST) Date: Tue, 7 Mar 2023 23:31:57 -0800 In-Reply-To: <20230308073201.3102738-1-avagin@google.com> Mime-Version: 1.0 References: <20230308073201.3102738-1-avagin@google.com> X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Message-ID: <20230308073201.3102738-3-avagin@google.com> Subject: [PATCH 2/6] sched: add WF_CURRENT_CPU and externise ttwu From: Andrei Vagin To: Kees Cook , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Christian Brauner , Chen Yu , avagin@gmail.com, Andrei Vagin , Andy Lutomirski , Dietmar Eggemann , Ingo Molnar , Juri Lelli , Peter Oskolkov , Tycho Andersen , Will Drewry , Vincent Guittot Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Oskolkov Add WF_CURRENT_CPU wake flag that advices the scheduler to move the wakee to the current CPU. This is useful for fast on-CPU context switching use cases. In addition, make ttwu external rather than static so that the flag could be passed to it from outside of sched/core.c. Signed-off-by: Peter Oskolkov Signed-off-by: Andrei Vagin --- kernel/sched/core.c | 3 +-- kernel/sched/fair.c | 4 ++++ kernel/sched/sched.h | 13 ++++++++----- 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index af017e038b48..386a0c40d341 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4123,8 +4123,7 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) * Return: %true if @p->state changes (an actual wakeup was done), * %false otherwise. */ -static int -try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) +int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) { unsigned long flags; int cpu, success = 0; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7a1b1f855b96..4c67652aa302 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7569,6 +7569,10 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) if (wake_flags & WF_TTWU) { record_wakee(p); + if ((wake_flags & WF_CURRENT_CPU) && + cpumask_test_cpu(cpu, p->cpus_ptr)) + return cpu; + if (sched_energy_enabled()) { new_cpu = find_energy_efficient_cpu(p, prev_cpu); if (new_cpu >= 0) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 3e8df6d31c1e..f8420e9ed290 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2093,12 +2093,13 @@ static inline int task_on_rq_migrating(struct task_struct *p) } /* Wake flags. The first three directly map to some SD flag value */ -#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ -#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ -#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ +#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ +#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ +#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ -#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ -#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ +#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ +#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ +#define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ #ifdef CONFIG_SMP static_assert(WF_EXEC == SD_BALANCE_EXEC); @@ -3232,6 +3233,8 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) extern void swake_up_all_locked(struct swait_queue_head *q); extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); +extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); + #ifdef CONFIG_PREEMPT_DYNAMIC extern int preempt_dynamic_mode; extern int sched_dynamic_mode(const char *str); -- 2.40.0.rc0.216.gc4246ad0f0-goog